Mobile power generator apparatus

ABSTRACT

Mobile power generator apparatus includes: left and right wheels attached to a frame having a power generator mounted therein; three guide rollers provided for each of the wheels for rotatably supporting the rim of the wheel at three positions of the rim; and mounting sections for respectively mounting the three guide rollers on a side wall of the frame, so that each of the wheels is rotatably supported by the three guide rollers on one of the side walls of the frame.

FIELD OF THE INVENTION

The present invention relates to mobile power generator apparatus inwhich the power generator is mounted in a frame and left and rightwheels are attached to the frame for carrying the power generator.

BACKGROUND OF THE INVENTION

Among the conventionally-known mobile power generator apparatus are onesin which the power generator is mounted in a frame, and in which leftand right wheels are attached to lower end portions of left and rightside walls of the frame for carrying the power generator and a pullinghandle is attached to an upper end portion of the frame. Such portablepower generator apparatus can be moved via the moving wheels by a useror human operator gripping a grip portion of the pulling handle to liftthe handle. One example of the mobile power generator apparatus of theaforementioned type is disclosed in Japanese Patent ApplicationLaid-Open Publication No. 2006-271122.

In the mobile power generator apparatus disclosed in the 2006-271122publication, an axle extends through the interior of the frame, the leftand right wheels are mounted on left and right end portions,respectively, of the axle. If the axle is provided to extend through arelatively high interior region of the frame, it would be difficult tosecure, inside the frame, a space for accommodating therein the powergenerator due to the presence of the axle. Thus, in the disclosed mobilepower generator apparatus, the axle is provided to extend through arelatively low interior region of the frame, so as to secure asufficient space for accommodating therein the power generator withoutbeing hindered by the axle. However; in the case where the axle extendsthrough a relatively low interior region of the frame, it is necessarythat the left and right wheels have a relatively small outer diameter,in order to reduce the overall height of the portable power generatorapparatus.

Generally, where the mobile power generator apparatus is used on anuneven surface, it can move more smoothly if the left and right wheelshave a greater outer diameter. With the left and right wheels having agreat outer diameter, however, the centers of the left and right wheelswould be located at a high position, and thus, the axle has to beprovided to extend through a relatively high interior region of theframe. In such a case, however, it is difficult to secure, inside theframe, a space for accommodating therein the power generator due to thepresence of the axle. Further, if the left and right wheels have a greatouter diameter, left and right side walls of the frame are covered withthe left and right wheels, which would make it difficult to form, inleft and right side walls of the frame, openings to be used formaintenance of the power generator.

SUMMARY OF THE INVENTION

In view of the foregoing prior art problems, it is an object of thepresent invention to provide an improved mobile power generatorapparatus which can have left and right wheels of a great outerdiameter, can have a sufficient space inside the frame for accommodatingtherein the power generator and can have, in left and right side wallsof the frame, openings to be used for maintenance of the powergenerator.

In order to accomplish the above-mentioned object, the present inventionprovides an improved mobile power generator apparatus, which comprises:left and right wheels mounted to a frame having a power generatormounted therein at least three guide rollers provided, for each of thewheels, for rotatably supporting a rim of the wheel at least threepositions of the rim; and mounting sections for respectively mountingthe at least three guide rollers, provided for each of the wheels, on aside wall of the frame. Thus, each of the left and right wheels isrotatably supported by the at least three guide rollers on one of theside walls (i.e., left or right side wall) of the frame.

Each of the left and right wheels can be provided on the left or rightside wall of the frame via the at least three guide rollers provided onthe left or right side wall. Thus, each of the left and right wheels canbe formed in a large outer diameter without the height of the framebeing increased. Further, with the rim of each of the left and rightwheels rotatably supported via the at least three guide rollers, thepresent invention can dispense with a conventional axle used to supportthe wheels. Thus, even where each of the wheels is formed in a largeouter diameter, it is not necessary that the axle extend through arelatively high interior region of the frame. As a result, the presentinvention can secure a space inside the frame for accommodating thereinthe power generator etc. even with the wheels formed in a large outerdiameter.

In an embodiment, the apparatus has a free space area formed at andaround the center of the rim. Thus, even with the wheels formed in alarge outer diameter, there can be secured a so-called maintenanceopening in the side walls.

Preferably, one of the at least three guide rollers, provided for eachof the rollers, is a movable roller supported via the mounting means insuch a manner that the movable guide roller is movable in a radialdirection of the rim, and the movable guide roller is normally urged bya resilient member in resilient abutment against the rim. Thus, it ispossible to absorb or accommodate a manufacturing error of the rim,which allows the rim to constantly rotate smoothly.

The following will describe embodiments of the present invention, but itshould be appreciated that the present invention is not limited to thedescribed embodiments and various modifications of the invention arepossible without departing from the basic principles. The scope of thepresent invention is therefore to be determined solely by the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain preferred embodiments of the present invention will hereinafterbe described in detail, by way of example only, with reference to theaccompanying drawings, in which:

FIG. 1 is a perspective view showing a mobile power generator apparatusaccording to an embodiment of the present invention;

FIG. 2 is a front view of the mobile power generator apparatus of thepresent invention

FIG. 3 is an exploded perspective view of the mobile power generatorapparatus of the present invention with its carriage unit detachedtherefrom for clarity;

FIG. 4 is a side view of the mobile power generator apparatus of thepresent invention with its right side cover detached therefrom;

FIG. 5 is a perspective view showing the carriage unit employed in themobile power generator apparatus of the present invention;

FIG. 6 is an enlarged view of an encircled section 6 of FIG. 4;

FIG. 7 is a sectional view taken along line 7-7 of FIG. 6;

FIG. 8 is an enlarged view of an encircled section 8 of FIG. 4;

FIG. 9 is a sectional view taken along line 9-9 of FIG. 8;

FIG. 10 is an exploded perspective view showing a pulling unit employedin the mobile power generator apparatus of the present invention;

FIG. 11 is a perspective view of the pulling unit in its expandedposition;

FIG. 12 is an enlarged view of an encircled section 12 of FIG. 4;

FIG. 13 is a side view showing the pulling unit in the expandedposition;

FIG. 14 is a sectional view taken along line 14-14 of FIG. 13;

FIG. 15 is an enlarged view of an encircled section 15 of FIG. 13;

FIG. 16 is a view explanatory of an example manner in which maintenance(repair and inspection) of the mobile power generator apparatus isperformed;

FIGS. 17A and 17B are views explanatory of an example manner in whichthe pulling unit is shifted to the expanded position;

FIGS. 18A and 18B are views showing the pulling unit having beenexpanded partway;

FIG. 19 is a view showing the pulling unit having been expanded to thepulling position;

FIGS. 20A and 20B are views explanatory of the pulling unit held in thepulling position;

FIG. 21 is a view explanatory of an example manner in which the mobilepower generator apparatus is pulled by a human operator via the pullingunit;

FIGS. 22A and 22B are views explanatory of an example manner in whichthe pulling unit is collapsed from the expanded position;

FIGS. 23A and 23B are views showing the pulling unit having beencollapsed partway;

FIGS. 24A and 24B are views showing the pulling unit having beencollapsed to a collapsed position; and

FIGS. 25A and 25B are views explanatory of an example manner in which apower cord is moved away from the left and right wheels by means of thepulling unit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference is now made to FIG. 1 showing in perspective a mobile powergenerator apparatus 10 according to an embodiment of the presentinvention, as well as to FIG. 2 showing in front elevation the mobilepower generator apparatus 10. The mobile power generator apparatus 10includes a frame 11 forming a framework of the power generator, anengine/power generator unit 12 (see also FIG. 4), a left side cover 13provided on the left side of the frame 11, a right side cover 14provided on the right side of the frame 11, a carriage unit 15 attachedto the frame 11, and a pulling unit 16 provided on a front section 11 aof the frame 11.

The frame 11 includes a bottom wall 21, an upper wall 22, a front wall23, a rear wall 24 (see FIG. 4), a left side wall 24 and a right sidewall 26, which together constitute a rectangular parallelepiped shape.Left and right leg portions 28 are vertically movably attached to alower end portion 24 a (see FIG. 4) of the rear wall 24.

The upper wall 22 has a fixed grip portion 31 provided on a substantialmiddle in a width or left-right direction (i.e., substantial widthwisemiddle) region of the power generator apparatus 10, and left and rightcassette accommodating portions 32 and 33 are provided to the left andright of the fixed grip portion 31.

The fixed grip portion 31 has front and rear ends 31 a and 31 b fixed tothe upper wall 22. The mobile power generator apparatus 10 can becarried by a user or human operator gripping the fixed grip portion 31with a hand to thereby lift the grip portion 31.

The left and right cassette accommodating portions 32 and 33 are eachprovided for accommodating therein a cassette gas canister 35 containinga gas fuel to be supplied to an engine 18 (see FIG. 4) of theengine/power generator unit 12. More specifically, the right cassetteaccommodating portion 33 is provided in a right half area of the upperwall 22 and has an openable/closable right cassette cover 36 attachedthereto. The cassette gas canister 35 can be loaded into the rightcassette accommodating portion 33 with the right cassette cover 36opened, and it is accommodated in the right cassette accommodatingportion 33 with the right cassette cover 36 kept in the closed position.The left cassette accommodating portion 32 is constructed and disposedin left-right symmetrical relation to the right cassette accommodatingportion 33, and thus, a detailed description of the left cassetteaccommodating portion 32 is omitted here.

FIG. 3 is an exploded perspective view of the mobile power generatorapparatus 10 with is carriage unit detached therefrom for clarity, andFIG. 4 is a side view of the mobile power generator apparatus 10 withthe right side cover 14 detached therefrom.

The right side wall 26 of the frame 11 has an outer periphery extendingalong the bottom wall 21, upper wall 22, front wall 23 and rear wall 24,and a water-resistant wall 41 of a substantially ring shape is providedinwardly of and with a predetermined gap from the outer periphery of theright side wall 26. Front resonator 42 is provided on a front endportion 41 a of the water-resistant wall 41, while a rear resonator 43is provided on a rear end portion 41 b of the water-resistant wall 41.

Right maintenance opening 45 is defined by upper and lower portions 41 cand 41 d of the water-resistant wall 41 and front and right resonators42 and 43. The right maintenance opening 45 is in communication with anaccommodating space 46 inside the frame 11 where the engine/powergenerator unit 12 is accommodated.

Two screw holes 48 are formed in diagonally opposite portions of thewater-resistant wall 41, and the right side cover 14 is detachablyattached at its circular outer peripheral portion 14 a to the right sidewall 26 by means of bolts 49 screwed into the screw holes 48.

The outer peripheral portion 14 a of the right side cover 14 is slightlygreater in size than an outer peripheral portion of the right side cover14. The right maintenance opening 45 is covered with the right sidecover 14 attached to the right side wall 26 by means of the two bolts49. Thus, by loosing the bolts 49 and detaching the right side cover 14from the right side wall 26 to thereby open the maintenance opening 45,repair and inspection (maintenance) of the engine/power generator unit12 can be performed through the maintenance opening 45.

The left side wall 25 is constructed and disposed in left-rightsymmetric relation to the aforementioned right side wall 26 and thuswill not be described in detail. Similarly to the right side wall 26,the left side wall 25 has an outer periphery extending along the bottomwall 21, upper wall 22, front wall 23 and rear wall 24, and a peripheralwall (not shown) is provided inwardly of and with a predetermined gapfrom the outer periphery of the left side wall 25.

Left maintenance opening (not shown) is defined by the peripheral walland in communication with the accommodating space 46. The leftmaintenance opening is covered with the left side cover 13. The leftside cover 13 is constructed and disposed in left-right symmetricrelation to the right side cover 14 and detachably attached to the leftside wall 25 by means of two bolts (not shown). Thus, by loosing the twobolts and detaching the left side cover 13 from the left side wall 25 tothereby open the left maintenance opening, maintenance of theengine/power generator unit 12 can be performed through the leftmaintenance opening.

The engine/power generator unit 12 comprises the engine 18 drivable witha gas fuel supplied from the cassette gas canister 35, and a powergenerator 19 mounted coaxially with the drive shaft (crankshaft) as theengine 18. Electric power is generated by the rotor (not shown) of thepower generator 19 being rotated by the engine 18.

As the engine 18 is driven, external air is directed into the rightmaintenance opening 45 through the gap between the right side cover 14and the water-resistant wall 41, during which time intake sound of theexternal air can be silenced in a resonating chamber defined by thefront and rear resonators 42 and 43.

The carriage unit 15 includes a right guide section 55 attached to theright side wall 26, a right wheel 56 rotatably supported via the rightguide section 55, a left guide section (not shown) attached to the leftside wall 25, a left wheel 58 (FIG. 2) rotatably supported via the leftguide section, and a caster section 61 provided on a lower end portion23 a of the front wall 23.

Because the left guide section is constructed and disposed in left-rightsymmetric relation to the right guide section 55, the followingdescription mainly describes in detail the right guide section 55 with adetailed description of the left guide section omitted. Further, becausethe left wheel 58 is constructed and disposed in left-right symmetricrelation to the right wheel 56, the following description mainlydescribes in detail the right wheel 56 with a detailed description ofthe left wheel 58 omitted.

FIG. 5 is a perspective view showing the carriage unit 15 employed inthe present invention. The right wheel 56 of the carriage unit 15includes a ring-shaped rim 64, and a tire disposed on and around theouter periphery of the rim 64. The rim 64 is made, for example, of resinor metal and has a ring-shaped ridge 67 (see also FIG. 7) formed on aninner peripheral wall 64 a and projecting radially inward. The rim 64 issupported via the right guide section 55 for rotation about a centeraxis 57.

The right guide section 55 includes first and second fixed guide rollers71 and 62, a movable guide roller 73, a first fixedly mounting section75 for rotatably mounting the first fixed guide roller 71 to the rightside wall 26 (see FIG. 4), a second fixedly mounting section 76 forrotatably mounting the second fixed guide roller 72 to the right sidewall 26, and a movably mounting section 77 for rotatably mounting themovable guide roller 73 to the right side wall 26.

The first and second fixed guide rollers 71 and 72 and the variableguide rollers 73 are at least three guide rollers employed in the mobilepower generator apparatus 10. Because the first and second fixed guiderollers 71 and 72 are identical in construction, the followingdescription will mainly describe in detail the first fixed guide roller71 with a detailed description of the second fixed guide roller 72omitted. Further, because the first and second fixedly mounting sections75 and 76 are identical in construction, the following description willmainly describe the first fixedly mounting section 75 with a detaileddescription of the second fixedly mounting section 76 omitted; whenevernecessary, elements of the second fixedly mounting section 76 will bementioned using the same reference characters as counterparts of thefirst fixedly mounting section 75.

FIG. 6 is an enlarged view of an encircled section 6 of FIG. 4, and FIG.7 is a sectional view taken along the 7-7 line of FIG. 6. The firstfixed guide roller 71 has a central through-hole 81 for mounting on thefirst fixedly mounting section 75, and an annular engagement groove orrecess 82 formed in the outer periphery 71 a for engagement with thering-shaped ridge 67 of the rim 64.

The first fixedly mounting section 75 includes a fixed-roller supportingbolt 84 for rotatably supporting the guide roller 71, a pair offixed-plate supporting bolts 85 provided on both sides of thefixed-roller supporting bolt 84 with predetermined intervals from thesupporting bolt 84, collars 86 fitted over the corresponding fixed-platesupporting bolts 85, a fixed plate 87 supported by the fixed-platesupporting bolts 85, and nuts 88 for fixing the fixed plate 87 to thefixed-roller supporting bolt 84 and pair of fixed-plate supporting bolts85.

The fixed-roller supporting bolt 84 has its head 84 a embedded in theright side wall 26 so that its shank projects from the right side wall26 toward the fixed plate 87. The pair of fixed-plate supporting bolts85, provided on both sides of the fixed-roller supporting bolt 84 and atpredetermined intervals from the bolt 84, have their heads 85 a embeddedin the right side wall 26 so that their shanks project from the rightside wall 26 toward the fixed plate 87.

The fixed plate 87 is a flat plate of a substantially triangular shape.The fixed plate 87 has a central through-hole 87 a formed centrallytherein for insertion therethrough of the fixed-roller supporting bolt84, and through-holes 87 b (see also FIG. 5) formed in its opposite endportions for insertion therethrough of the fixed-plate supporting bolts85.

In the first fixedly mounting section 75, the mounting hole 81 of thefirst fixed guide roller 71 is fitted over the fixed-roller supportingbolt 84, and the collars 86 are fit over the corresponding fixed-platesupporting bolts 85. Further, the central through-hole 87 a of the fixedplate 87 is fitted over the fixed-roller supporting bolt 84, and thethrough-holes 87 b of the fixed plate 87 is fitted over the fixed-platesupporting bolts 85.

The fixed-roller supporting bolt 84 has a threaded portion 84 bprojecting out of the central through-hole 87 a and screwed into one ofthe nuts 88, and the fixed-plate supporting bolts 85 have theirrespective threaded portions 85 b projecting out of the through-holes 87b and screwed into the other nuts 88.

Thus, the first fixed guide roller 71 is rotatably supported by thefixed-roller supporting bolt 84 and prevented by the fixed plate 87 fromaccidentally getting out of engagement with the fixed-roller supportingbolt 84. In such a state, the ridge 67 of the rim 64 fits in theengagement recess 82 of the first fixed guide roller 71, and a bottomsurface 82 a of the engagement recess 82 is kept in abutment against aninner peripheral surface 67 a of the ridge 67.

Referring back to FIG. 5, the second fixed guide roller 72 is identicalin construction to the first fixed guide roller 71, and the secondfixedly mounting section 76 is identical in construction to the firstfixedly mounting section 75. The ridge 67 of the rim 64 fits in anengagement recess 91 of the second fixed guide roller 72, and the bottomsurface of the engagement recess 91 is kept in abutment against an innerperipheral surface 67 a of the ridge 67. The engagement recess 91 of thesecond fixed guide roller 72 is identical in shape to the engagementrecess 82 of the first fixed guide roller 71.

FIG. 8 is an enlarged view of an encircled section 8 of FIG. 4, and FIG.9 is a sectional view taken along the 9-line of FIG. 8. The movableguide roller 73 has a mounting hole 93 formed centrally through thethickness thereof for mounting the guide roller 73 to the movablymounting section 77, and it has an annular engagement recess 94 formedalong the outer periphery 73 thereof for fitting engagement with theridge 67 of the rim 64. Note that the movable guide roller 73 isidentical in shape to the first and second fixed guide rollers 71 and72.

The movably mounting section 77 includes a movable-roller supportingbolt 95 for rotatably supporting the movable guide roller 73, a pair ofmovable-plate supporting bolts 96 provided on both sides of themovable-roller supporting bolt 95 with predetermined intervals from thesupporting bolt 95, collars 97 fitted over the correspondingmovable-plate supporting bolts 96, inner and outer movable plates 98 and99 supported by the movable-plate supporting bolts 96, and nuts 101 forfixing the inner and outer movable plates 98 and 99 to themovable-roller supporting bolt 95 and pair of movable-plate supportingbolts 96. The movably mounting section 77 also includes a supportingshaft portion 103 for pivotably supporting respective one end portions98 a and 99 a of the inner and outer movable plates 98 and 99, a slidingshaft portion 104 for pivotably supporting respective other end portions98 b and 99 b of the inner and outer movable plates 98 and 99, and abiasing section 105 for normally urging the movable-roller supportingbolt 95 toward the rim 64.

The movable-roller supporting bolt 95 has its head 95 a embedded in theinner movable plate 98 so that its shank projects from the inner movableplate 98 toward the outer movable plate 99. The pair of movable-platesupporting bolts 96, provided on both sides of the movable-rollersupporting bolt 95 and at predetermined intervals from the bolt 95, havetheir heads 96 a embedded in the inner movable plate 98 so that theirshanks project from the inner movable plate 98 toward the outer movableplate 99.

The inner movable plate 98 is a flat plate of a curved shape. The head95 a of the movable-roller supporting bolt 95 is embedded in a centralportion of the inner movable plate 98, and the heads 96 a of themovable-plate supporting bolts 96 are embedded in portions, located atboth sides of the bolt 95, of the inner movable plate 98. Further, athrough-hole 98 c is formed in one end portion 98 a of the inner movableplate 98, while a slide hole 98 d is formed in another end portion 98 bof the plate 98.

The through-hole 98 c is a hole through which a supporting shaft bolt107 of the supporting shaft portion 103 is inserted. The slide hole 98 dis an elongated hole through which a bolt 112 of the sliding shaftportion 104 is inserted for sliding movement along the edge the slidehole 98 d.

The outer movable plate 99 is a flat plate of a curved shape similarlyto the inner movable plate 98. The outer movable plate 99 has a centralthrough-hole 99 c formed centrally therein, and through-holes 99 dformed in its intermediate portions, located on both sides of thecentral through-hole 99 c, for insertion therethrough of themovable-plate supporting bolts 96. Further, a through-hole 99 e isformed in one end portion 99 a of the outer movable plate 99, while aslide hole 99 f is formed in another end portion 99 b of the plate 99.

The through-hole 99 e is a hole through which the supporting shaft bolt107 of the supporting shaft portion 103 is inserted. The slide hole 99 fis an elongated hole through which the bolt 112 of the sliding shaftportion 104 is inserted for sliding movement along the edge of the slidehole 99 f.

The supporting shaft portion 103 includes a supporting shaft nut 106, asupporting shaft bolt 107 screwed in the nut 106, and first and secondsupporting shaft collars 108 and 109 fitted over the shaft bolt 107. Thefirst supporting shaft collar 108 is inserted through the through-hole98 c of the inner movable plate 98 and through-hole 99 e of the outermovable plate 99.

The first supporting shaft collar 108 is sandwiched between the innerand outer movable plates 98 and 99, and the second supporting shaftcollar 109 is sandwiched between the inner movable plate 98 and theright side wall 26.

The sliding shaft portion 104 includes a sliding shaft nut 111 embeddedin the right side wall 26, a sliding shaft bolt 112 screwed in the nut111, and first and second sliding shaft collars 113 and 114 fitted overthe sliding shaft bolt 112. The sliding shaft bolt 112 is slidablyinserted through the slide hole 98 d of the inner movable plate 98, andthrough the slide hole 99 f of the outer movable plate 99 for slidingmovement along the edge of the slide hole 99 f.

The first sliding shaft collar 113 is sandwiched between the inner andouter movable plates 98 and 99, and the second sliding shaft collar 114is sandwiched between the inner movable plate 98 and the right side wall26.

The biasing section 105 includes an upper stopper portion 115 providedon the inner movable plate 98, a lower stopper portion 116 provided onthe right side wall 26, and a compression spring (resilient member) 117interposed between the upper and lower stopper portions 115 and 116.

In the movably mounting section 77, the mounting hole 93 of the movableguide roller 73 is fitted over the movable-roller supporting bolt 95,and the collars 97 are fitted over the two movable-plate supportingbolts 96.

Further, the central through-hole 99 c of the outer movable plate 99 isfitted over the movable-roller supporting bolt 95, and the through-holes99 d of the outer movable plate 99 are fitted over the two movable-platesupporting bolts 96.

The movable-roller supporting bolts 95 has a threaded portion 95 bprojecting out of the central through-hole 99 c and screwed in one ofthe nuts 101, and the movable-plate supporting bolts 96 have theirthreaded portions 96 b projecting out of the corresponding through-holes99 d and screwed into the other nuts 101.

Thus, the movable guide roller 73 is rotatably supported by themovable-roller supporting bolt 95 and prevented by the movable plates 98from accidentally getting out of engagement with the movable-rollersupporting bolt 95.

Further, the supporting shaft bolt 107 is inserted through thethrough-holes 98 c and 99 e of the inner and outer movable plates 98 and99, and the first and second supporting shaft collars 108 and 109 arefitted over the supporting shaft bolt 107. Threaded portion 107 a of thesupporting shaft bolt 107 projecting out of the second supporting shaftcollar 109 is screwed in the supporting shaft nut 106.

Further, the sliding shaft bolt 112 is inserted through the slide holes98 d and 99 f of the inner and outer movable plates 98 and 99, and thefirst and second sliding shaft collars 113 and 114 are fitted over thesliding shaft bolt 112. Threaded portion 112 a of the sliding shaft bolt112 projecting out of the second sliding shaft collar 114 is screwedinto the sliding shaft nut 111.

Thus, the inner and outer movable plates 98 and 99 are pivotable aboutthe supporting shaft bolt 107 toward and away the rim 64 as indicated byarrows of FIG. 8. In the aforementioned manner, the movable guide roller73 is supported in such a manner that it is movable in the radialdirection of the rim 64.

The compression spring 117 is interposed between the upper and lowerstopper portions 115 and 116 so that the movable guide roller 73 isnormally pressed against the rim 64 by the biasing force of thecompression spring 117. Thus, the engagement recess 94 of the movableguide roller 73 is normally resiliently fitted over the ridge 67 of therim 64, and the outer periphery 73 a of the movable guide roller 73 isnormally resiliently abutted against the inner peripheral wall 64 a ofthe rim 64. In the aforementioned manner, it is possible to absorb oraccommodate a manufacturing error of the rim 64, and thus, the rim 64can be rotated smoothly.

As described above, the right wheel 56 is rotatably supported, on theright side wall of the frame 11, by the right wheel 56 (i.e., rim 64)being supported by the first and second fixed guide rollers 71 and 72and the movable guide roller 73. Therefore, the right wheel 56 can beformed in a large outer diameter D without the height H1 of the frame 11being increased. In the above-described embodiment, the outer diameter Dof the right wheel 56 is set substantially equal to the height H1 of theframe 11.

Further, with the rim 64 rotatably supported via the first and secondfixed guide rollers 71 and 71 and movable guide roller 73, the instantembodiment can dispense with a conventional axle used to support thewheel; thus, even where the wheel 56 is formed in a large outerdiameter, it is not necessary that the axle extend through a relativelyhigh interior region of the frame 11. Thus, the instant embodiment cansecure the space 46 (FIG. 4) for accommodating therein the engine/powergenerator unit 12 etc. even with the wheel 56 formed in a large outerdiameter.

Further, by dispensing with the conventional axle used to support thewheel, the apparatus 10 has a sufficient free space area 121 secured atand around the center of the rim 64 (hereinafter also referred to as“central area 121”). Further, because the central area 121 faces theopening 45 (see also FIG. 4) of the side wall 26, maintenance operationcan be performed using the central area 121 of the rim 64 and opening 45of the side wall 26.

Furthermore, as set forth above, the left guide section of the carriageunit 15 is constructed and disposed in left-right symmetric relation tothe right guide section 55, and the left wheel 58 is constructed anddisposed in left-right symmetric relation to the right wheel 56. Thus,similarly to the right wheel 56, the left wheel 58 is rotatably disposedon the left side wall 25 of the frame 11.

Referring back to FIGS. 1 and 2, the caster section 61 is provided onthe lower end portion 23 a of the front wall 23. The caster section 61includes a pivot shaft 124 rotatably mounted on the front wall 23, abracket 125 fixed to the pivot shaft 124, a steering wheel 126 rotatablysupported on the bracket 125, and a caster stopper 185 fixed to thebracket 125.

In the caster section 61, the steering wheel 126 has a centerline 128offset from a downward extension line of the pivot shaft 124 by adistance L1 as shown in FIG. 1 and FIG. 11 as well.

When the mobile power generator apparatus 10 is to be moved via the leftand right wheels 58 and 56, the orientation (i.e., operating direction)of the steering wheel 126 can be changed in accordance with a directionwhere the mobile power generator apparatus 10 is to be moved (i.e.,moving direction of the mobile power generator apparatus 10).

Further, in the caster section 61, the steering wheel 126 is verticallypivotably supported on a support shaft 129 and normally urged downwardby a spring member (not shown). Thus, as the mobile power generatorapparatus 10 is moved via the left and right wheels 58 and 56 on anuneven ground surface, the steering wheel 126 can be pivotally moved upand down in response to the unevenness of the ground surface.

Because the orientation (i.e., operating direction) of the steeringwheel 126 can be changed in accordance with the moving direction of themobile power generator apparatus 10 and pivotally moved up and down inresponse to the unevenness of the ground surface, the mobile powergenerator apparatus 10 can achieve an enhanced mobility and operability.

Further, the steering wheel 126 can be held in a stationary state by alongitudinal middle portion 138 c of a lower connecting rod 138 beingbrought to engagement with the caster stopper 185. Details of thelongitudinal middle portion 138 c of the lower connecting rod 138 willbe discussed later with reference to FIGS. 10 and 11.

Further, in the instant embodiment of the mobile power generatorapparatus 10, the left and right leg portions 28 are vertically movablyattached to the lower end portion 24 a (see FIG. 4) of the rear wall 24.Each of the left and right leg portions 28 can be locked at a stationaryposition for retaining the mobile power generator apparatus 10 in thestationary state and a moving position for retaining the mobile powergenerator apparatus 10 in a movable state. The stationary position is alowered position of the leg portion 28, while the moving position is araised position of the leg portion 28.

FIG. 10 is an exploded perspective view showing the pulling unit 16employed in the instant embodiment of the mobile power generatorapparatus 10, and FIG. 11 is a perspective view of the pulling unit 16in an expanded position. The pulling unit 16 is provided on the frontsection 11 a of the frame 11 and operable by the human operator to pullthe mobile power generator apparatus 10.

The pulling unit 16 includes a right pivoting link unit 132 provided ona right side portion 131 of the front section 11 a, a right link cover133 covering the right pivoting link unit 132, a left pivoting link unit136 provided on a left side portion 35 of the front section 11 a, a leftlink cover 137 covering the left pivoting link unit 136, theabove-mentioned lower connecting rod 138 interconnecting the rightpivoting link unit 132 and the left pivoting link unit 136, and apulling handle 141 connected at opposite ends to the right and leftpivoting link units 132 and 136.

Because the left and right pivoting link units 136 and 132 areconstructed and disposed in left-right symmetric relation to each other,the following description mainly describes in detail the right pivotinglink unit 132 with a detailed description of the left pivoting link unit136 omitted. Further, because the left and right link covers 137 and 133are constructed and disposed in left-right symmetric relation to eachother, the following description mainly describes in detail the rightlink cover 133 with a detailed description of the left link cover 137omitted.

The right pivoting link unit 132 includes a right upper pivoting link145 vertically pivotably supported on the right side portion 131 of thefront section 11 a, and a right lower pivoting link 146 verticallypivotably supported on the right side portion 131 of the front section11 a. The right upper pivoting link 145 and right lower pivoting link146 are disposed parallel to each other.

The right upper pivoting link 145 is formed in a curved shape to extendalong the front wall 23 of the frame 11, and it has an upper end portion145 a pivotably connected, by means of a bolt 147, to a first uppermounting portion (upper end portion) 131 a of the right side portion131.

The right lower pivoting link 146 is formed in a curved shape to extendalong the right upper pivoting link 145 and has a right tire stopper 158provided near its upper end portion 146 a and projecting toward theright wheel 56. The right lower pivoting link 146 is pivotably connectedat the upper end portion 146 a to a second upper mounting portion (upperend portion) 131 b of the right side portion 131 by means of a bolt 147.The second upper mounting portion 131 b is located slightly forwardlyand downwardly of the first upper mounting portion 131 a.

As shown in FIG. 4, the right tire stopper 158 is a member that abutsagainst the outer periphery of the right wheel 56 when the pullinghandle 141 is in a collapsed position. By the right tire stopper 158abutting against the outer periphery of the right wheel 56, the rotationof the wheel 56 can be prevented. Namely, the rotation of the wheel 56can be prevented as desired by the simple construction calling for onlythe tire stopper 158.

The right lower pivoting link 146 is located immediately below andparallel to the right upper pivoting link 145. The right lower pivotinglink 146 and right upper pivoting link 145 are supported together forintegral vertical pivoting movement about their respective upper endportions 146 a and 145 a.

The right lower pivoting link 146 and right upper pivoting link 145 arecovered with the right link cover 133. The right link cover 133 has anupper end portion 133 a that is pivotably connected, by means of thebolt 147, to the first upper mounting portion 131 a along with the upperend portion 145 a of the right upper pivoting link 145, and the rightlink cover 133 is fixed at its lower end portion 133 b to a lower endportion (lower boss) 145 b of the right upper pivoting link 145.

The right link cover 133 has a substantially U cross-sectional shape andhas the right upper and right lower pivoting links 145 and 146accommodated in its interior space 149 (see also FIG. 14). The rightlink cover 133 has a handle holder 153 formed on a substantiallongitudinal middle portion of an inner wall thereof. The handle holder153 has a substantially U cross-sectional shape so as to sandwichinglyhold a right handle section 161 of the pulling handle 141.

FIG. 12 is an enlarged view of an encircled section 12 of FIG. 4. Theright link cover 133 has a holding recess 152 formed in the lower endportion 133 d of an outer wall 133 d. The holding recess 152 has acurved shape such that it can engage a lower end portion (or lower boss)146 b of the right lower pivoting link 146. The holding recess 152 andlower end portion (or lower boss) 146 b of the right lower pivoting link146 together constitute a right holding section 151. Details of theright holding section 151 will be discussed later with reference toFIGS. 13-15.

Referring back to FIGS. 10 and 11, the lower end portion 145 b of theright upper pivoting link 145 and lower end portion 155 b of a leftupper pivoting link 155 are interconnected via the above-mentioned lowerconnecting rod 138.

More specifically, the lower connecting rod 138 has a right end portion138 a connected to the lower end portion 145 b of the right upperpivoting link 145, and a left end portion 138 b connected to a lower endportion 155 b of the left upper pivoting link 155.

The longitudinal middle portion 138 c of the lower connecting rod 138 isbent to project forward, so that the middle portion 138 c is located ata position where it can engage with the caster stopper 185. The righthandle section 161 of the pulling handle 141 is connected to the lowerend portion 145 b of the right upper pivoting link 145 and lower endportion 146 b of the right lower pivoting link 146.

Further, a left handle section 162 of the pulling handle 141 isconnected to the lower end portion 155 b of the left upper pivoting link155 and lower end portion 156 b of the left lower pivoting link 156.

The pulling handle 141 includes the above-mentioned right handle section161 located inwardly of the right link cover 133, i.e. closer to thelongitudinal centerline of the mobile power generator apparatus 10 thanthe right link cover 133 (see also FIG. 2), the above-mentioned lefthandle section 162 located inwardly of the left link cover 137, i.e.closer to the longitudinal centerline of the mobile power generatorapparatus 10 than the left link cover 137 (see also FIG. 2), aconnecting section 163 interconnecting respective distal ends 161 a and162 a of the right and left handle sections 161 and 162, and a movablegrip portion 164 provided concentrically with the connecting section163.

The right handle section 161 is located closer to the longitudinalcenterline of the mobile power generator apparatus 10 than the rightlink cover 133 with a predetermined interval from the right upperpivoting link 145 and right lower pivoting link 146.

The right handle section 161 has first and second lower mountingportions 167 and 168 formed on its proximal end portion 161 b. The righthandle section 161 is pivotably connected at the first lower mountingportion 167 to the lower end portion 145 b of the right upper pivotinglink 145 by means of a bolt 171, and also pivotably connected at thesecond lower mounting portion 168 to the lower end portion 146 b of theright lower pivoting link 146 by means of a bolt 171.

The left handle section 162 is constructed and disposed in left-rightsymmetric relation to the right handle section 161, and thus, thefollowing description mainly describes in detail the right handlesection 161 with a detailed description of the left handle section 162omitted; whenever necessary, elements of the left handle section 162will be mentioned using the same reference characters as counterparts ofthe right handle section 161.

Namely, in the pulling handle 141, the right handle section 161 isconnected at its proximal end portion 161 b to the respective lower endportions 145 b and 146 b of the right upper pivoting link 145 and rightlower pivoting link 146 in such a manner that the right handle section161 is movable in interlocking relation to the pivoting links 145 and146, and the left handle section 162 is connected at its proximal endportion 162 b to the respective lower end portions 155 b and 156 b ofthe left upper pivoting link 155 and left lower pivoting link 156 insuch a manner that the left handle section 162 is movable ininterlocking relation to the pivoting links 155 and 156. Further, themovable grip portion 164 is provided on the connecting section 163interconnecting the respective distal ends 161 a and 162 a of the rightand left handle sections 161 and 162.

The pulling unit 16 is also constructed so that the pulling handle 141is expandable in a direction where the movable grip portion 164 movesaway from the right and left pivoting link units 132 and 136 ininterlocked relation to upward pivotal movement of the link units 132and 136.

The pulling unit 16 is constructed so that the pulling handle 141 iscollapsible in a direction where the movable grip portion 164 movestoward the right and left pivoting link units 132 and 136 in interlockedrelation to downward pivotal movement of the link units 132 and 136.

Namely, the pulling unit 16 is collapsible or bendable at itssubstantial longitudinal middle portion. Further, the right and leftpivoting link units 132 and 136 each have a length substantially equalto a length of the pulling handle 141. Thus, the pulling unit 16 canhave an increased overall length when it is in the expanded position anda reduced overall length when it is in the collapsed (or retracted)position.

Further, in the pulling handle 141, the right handle section 161 isconnected at the first and second lower mounting portions 167 and 168 tothe lower end portions 145 b and 146 b, respectively, of the right upperpivoting link 145 and right lower pivoting link 146, and the left handlesection 162 is connected at the first and second lower mounting portions167 and 168 to the lower end portions 155 b and 156 b, respectively, ofthe left upper pivoting link 155 and left lower pivoting link 156.

Namely, the right handle section 161 is connected at the proximal endportion 161 b to the lower end portions 145 b and 146 b of the rightupper pivoting link 145 and right lower pivoting link 146, while theleft handle section 162 is connected at the proximal end portion 162 bto the lower end portions 155 b and 156 b of the left upper pivotinglink 155 and left lower pivoting link 156.

Thus, the pulling handle 141 is prevented from moving independently ofthe lower end portions 145 b and 146 b and lower end portions 155 b and156 b. Consequently, when the pulling handle 141 is moved or shifted tothe collapsed or expanded position, the movement of the pulling handle141 can be controlled by the right and left pivoting link units 132 and136 in such a manner that the movable grip portion 164 moves in apredetermined trajectory 181 (FIG. 18A).

FIG. 13 is a side view showing the pulling unit 16 of the mobile powergenerator apparatus 10 in the expanded position, FIG. 14 is a sectionalview taken along the 14-14 line of FIG. 13, and FIG. 15 is an enlargedview of an encircled section 15 of FIG. 13.

As the pulling handle 141 is expanded so that the movable grip portion164 is shifted from a retracted position P1 (FIG. 4) to a pullingposition P2, not only the right lower pivoting link 146 interferes withthe right upper pivoting link 145, but also the left lower pivoting link156 interferes with the left upper pivoting link 155.

More specifically, the lower end portion (lower boss) 146 b of the rightlower pivoting link 146 interferes with a region 145 c of the rightupper pivoting link 145 near the lower end portion 145 b. The lower endportion (lower boss) 146 b is oriented toward the near-lower-end region145 c. Thus, the lower end portion 146 b can be reliably abutted againstthe near-lower-end region 145 c of the right upper pivoting link 145.

Similarly, the lower end portion (lower boss) 156 b of the left lowerpivoting link 156 interferes with a region 155 c of the left upperpivoting link 155 near the lower end portion 155 b. The lower endportion (lower boss) 156 b is oriented toward the near-lower-end region145 c. Thus, the lower end portion 156 b can be reliably abutted againstthe near-lower-end region 155 c of the left upper pivoting link 155.

With such arrangements, the pulling handle 141 can be prevented frombeing expanded beyond the pulling position P2. Thus, the instantembodiment can dispense with a separate stopper that was required in theprior art to prevent the pulling handle 141 from being expanded beyondthe pulling position, and consequently, the instant embodiment of themobile power generator apparatus 10 can be simplified in construction.

The pulling unit 16 further includes right and left retaining sections151 and 191. The right retaining section 151 has a retaining recess 152,and it includes the lower end portion (lower boss) 146 b of the rightlower pivoting link 146. The left retaining section 191 is constructedand disposed in left-right symmetric relation to the right retainingsection 151, and thus, the following description mainly describes indetail the right retaining section 151 with a detailed description ofthe left retaining section 191 omitted; whenever necessary, elements ofthe left retaining section 191 will be mentioned using the samereference characters as counterparts of the right retaining section 151.

As the pulling handle 141 is expanded so that the movable grip portion164 is shifted to the pulling position P2 where the human operator canpull the movable grip portion 164, the lower end portion (lower boss)146 b of the right lower pivoting link 146 is fitted into the retainingrecess 152 while the lower end portion (lower boss) 156 b of the leftlower pivoting link 156 is fitted into the left retaining recess 152. Inthis way, the pulling handle 141 can be prevented from beingaccidentally collapsed by the weights of the pulling handle 141, rightand left pivoting link units 132 and 136, etc.

Next, with primary reference to FIG. 16, a description will be givenabout an example manner in which maintenance (repair and inspection) ofthe mobile power generator apparatus 10 is performed. First, the twobolts 49 are removed from the screw holes 48, and the right side cover14 is detached from the right side wall section 26 to open the centralarea 121 of the rim 64 and opening 45.

Air cleaner 193 of the engine 18, engine oil cap 194, carburetor 195,mixer (not shown) are provided at positions facing the maintenanceopening 45. Thus, with the maintenance opening 45 opened in theaforementioned manner, it is possible to replace an element of the aircleaner 193, remove the engine oil cap 194 to thereby replace engineoil, and replace the carburetor 195 and mixer. The mixer is a devicethat mixes the gas fuel, supplied from the cassette canister 35, withair introduced via the air cleaner and feeds a resultant fuel/air mixinto the cylinder of the engine 18.

Thus, maintenance (repair and inspection) of the mobile power generatorapparatus 10 can be performed through the central area 121 andmaintenance opening 45.

Next, with reference to FIGS. 17 to 21, a description will be givenabout an example of how to pull the mobile power generator apparatus 10using the pulling unit 16 after shifting the pulling unit 16 from thecollapsed position P1 to the pulling position P2. In FIGS. 17 to 21,only the construction of the right side of the pulling unit 16 is shownwith the construction of the left side of the pulling unit 16 omitted,to simplify illustration and facilitate understanding of the pullingunit 16.

FIGS. 17A and 17B are views explanatory of how the pulling unit 16 isshifted to the expanded position; FIG. 17B is an enlarged view of anencircled section 17 b of FIG. 17A. In FIG. 17A, the pulling unit 16 isshown as being in the collapsed position P1. The lower end portion(lower boss) 146 b of the right lower pivoting link 146 is located belowthe retaining recess 152. Under this condition, the human operatorstarts expanding the pulling unit 16 by gripping the movable gripportion 164 with a hand 198 and pulling the pulling unit 16 toward thepulling position P2 (see FIG. 19) as indicated by arrow A. During thattime, the right upper and right lower pivoting links 145 and 146 pivotupward about the bolts 147 as indicated by arrow B. At the same time,the lower end portion (lower boss) 146 b of the right lower pivotinglink 146 angularly moves about the lower end portion (lower boss) 145 bof the right upper pivoting link 145 as indicated by arrow C of FIG.17B.

FIGS. 18A and 18B are views showing the pulling unit 16 having beenexpanded partway; FIG. 18B is an enlarged view of an encircled section18 b of FIG. 18A. As the human operator continues to pull the movablegrip portion 164 toward the pulling position P2 as indicated by arrow A,the movable grip portion 164 continues to move in the predeterminedtrajectory 181. During that time, the right upper and right lowerpivoting links 145 and 146 continue to pivot upward about the bolts 147as indicated by arrow B, and the lower end portion (lower boss) 146 b ofthe right lower pivoting link 146 angularly moves toward the retainingrecess 152.

FIG. 19 is a view showing the pulling unit 16 having been expanded tothe pulling position P2. By the human operator further pulling themovable grip portion 164 toward the pulling position P2 as indicated byarrow A, the movable grip portion 164 further moves in the predeterminedtrajectory 181 to reach the pulling position P2.

FIGS. 20A and 20B are views showing the pulling unit 16 having beenexpanded to the pulling position P2. More specifically, FIG. 20A is asectional view taken along the 20 a-20 a line of FIG. 19, and FIG. 20Bis an enlarged view of an encircled portion 20 b of FIG. 19.

The lower end portion (lower boss) 146 b of the right lower pivotinglink 146 interferes with the near-lower-end region 145 c of the rightupper pivoting link 145. Thus, the pulling handle 141 can be preventedfrom being expanded beyond the pulling position P2.

At the same time the lower end portion (lower boss) 146 b of the rightlower pivoting link 146 interferes with the near-lower-end region 145 c,the lower end portion (lower boss) 146 b of the right lower pivotinglink 146 fits into the retaining recess 152 of the right retainingsection 151.

In this way, the pulling handle 141 can be prevented from beingaccidentally collapsed by the weights of the pulling handle 141,pivoting link units 132, etc. Thus, the movable grip portion 164 can beretained in the pulling position P2 even while the human operator's handis off the grip portion 164. As a consequence, the instant embodimentcan enhance the usability of the mobile power generator apparatus 10.

Referring back to FIG. 19, the pulling unit 16 is bendable at itssubstantial longitudinal middle portion. Further, the right and leftpivoting link units 132 and 136 each have a length substantially equalto the length of the pulling handle 141. Thus, the pulling unit 16 canhave an increased overall length by being expanded to the expandedposition.

Further, as the pulling handle 141 is expanded, the right upper andright lower pivoting links 145 and 146 pivot upward about the bolts 147,so that the lower end portions (lower bosses) 145 b and 146 b of theright lower pivoting links 145 and 146 move upward. Thus, the pullinghandle 141 connected with the lower end portions (lower bosses) 145 band 146 b is lifted, so that the movable grip portion 164 of the pullinghandle 141 can be located at a high position H2.

Further, because the right upper and right lower pivoting links 145 and146 pivot upward about the bolts 147 as the pulling handle 141 isexpanded, the lower end portions (lower bosses) 145 b and 146 b of theright lower pivoting links 145 and 146 move forward, and thus, thepulling handle 141 connected with the lower end portions (lower bosses)145 b and 146 b also moves forward. By the pulling handle 141 movingforward like this, the movable grip portion 164 of the pulling handle141 can be located at a great distance L2 from the frame 11.

FIG. 21 is a view showing an example manner in which the mobile powergenerator apparatus 10 is pulled by the human operator via the pullingunit 16. As illustrated in the figure, the human operator 197 walksforward gripping the movable grip portion 164 with the hand 198. In thisway, the right and left wheels 56 and 58 rotate, and thus, the mobilepower generator apparatus 10 can be pulled forward. During that time,the left and right leg portions 28 are kept locked in the movingposition, and the movable grip portion 164 is held at the high positionH2. Namely, the movable grip portion 164 of the pulling handle 141shifted to the expanded position can be held at a suitable heightcorresponding to the height of the human operator's hand.

Further, in the state shown in FIG. 11, the movable grip portion 164 islocated forwardly of and at the great distance L2 from the frame 11, andthus, the body of the mobile power generator apparatus 10 is located ata sufficient distance from the human operator, which can prevent thehuman operator 197 from contacting the body of the mobile powergenerator apparatus 10.

Because the movable grip portion 164 of the pulling handle 141 shiftedto the expanded position can be held at a suitable height correspondingto the height of the human operator's hand and the human operator 197can be prevented from contacting the body of the mobile power generatorapparatus 10, the instant embodiment can achieve an enhanced mobilityand operability of the mobile power generator apparatus 10.

As the mobile power generator apparatus 10 is pulled by the humanoperator, the steering wheel 126 can be changed in orientation inaccordance with a moving direction of the power generator apparatus 10and moved up and down in accordance with unevenness of the groundsurface. As a consequence, the mobility of the mobile power generatorapparatus 10 can be even further enhanced.

Next, with reference to FIGS. 22 to 24, a description will be givenabout an example manner in which the pulling unit 16 of the mobile powergenerator apparatus 10 is shifted from the pulling position P2 to thecollapsed position P1. In FIGS. 22 to 24, only the construction of theright side of the pulling unit 16 is shown with the construction of theleft side of the pulling unit 16 omitted, to simplify illustration andfacilitate understanding of the pulling unit 16.

FIGS. 22A and 22B are views showing an example manner in which thepulling unit 16 is collapsed from the expanded position; FIG. 22B is anencircled portion 22 b of FIG. 22A. As the movable grip portion 164 ispushed with a force as indicated by arrow F1, the pulling handle 141pivots as indicated by arrow D about the lower end portion (lower boss)145 b of the right upper pivoting link 145, and simultaneously the lowerend portion (lower boss) 146 b of the right lower pivoting link 146pivots as indicated by arrow E about the lower end portion (lower boss)145 b of the right upper pivoting link 145. By pivoting as indicated byarrow E, the lower end portion (lower boss) 146 b of the right lowerpivoting link 146 gets out of engagement with, and thus is released fromretention by, the retaining recess 152 of the right link cover 133.

Then, the right upper pivoting link 145 and the right lower pivotinglink 146 start pivoting downward as indicated by arrow F about the bolts147 due to the weights of the pulling handle 141, pivoting link unit132, etc. Thus, the movable grip portion 164 starts collapsing towardthe collapsed position P1 in the predetermined trajectory 181 asindicated by arrow G.

FIGS. 23A and 23B are views showing the pulling unit 16 having beencollapsed partway. In this state, the right upper pivoting link 145 andthe right lower pivoting link 146 further pivots downward as indicatedby arrow F due to the weights of the pulling handle 141, pivoting linkunit 132, etc. Thus, the movable grip portion 164 moves toward thecollapsed position P1 in the predetermined trajectory 181 as indicatedby arrow G.

FIGS. 24A and 24B are views showing the pulling unit 16 having beingcollapsed to the collapsed position P1. As shown in FIG. 24A, themovable grip portion 164 moves in the predetermined trajectory 181 (seeFIG. 23) as indicated by arrow G to reach a position immediately shortof the collapsed position P1. Then, the human operator pushes themovable grip portion 164 toward the frame 11 as indicated by arrow F2.

Thus, as shown in FIG. 24B, the right handle section 161 is engaged bythe handle holder 153 of the right link cover 133, while the left handlesection 162 is engaged by the handle holder 154 of the left link cover137. In this way, the pulling handle 141 can be retained in thecollapsed position P1 (see FIG. 24A).

As described above in relation to FIGS. 17-24, the mobile powergenerator apparatus 10 is constructed in such a manner that the movablegrip portion 164 moves in the predetermined trajectory 181 (see FIGS. 19and 22) as the pulling handle 141 is shifted from the collapsed positionP1 to the expanded position P2. Thus, the human operator 197 can readilycollapse/expand the pulling handle 141 by just shifting the hand 198,gripping the movable grip portion 164, along the predeterminedtrajectory 181. As a result, the operation to be performed by the humanoperator 197 when collapsing/expanding the pulling handle 141 can befacilitated, which can significantly enhance the usability of the powergenerator apparatus 10.

Further, the movement trajectory 181 of the movable grip portion 164 canbe set to have a substantially constant gradient (more specifically asubstantially S-shaped gradient) from the collapsed position P1 to theexpanded position P2, as seen in FIG. 19. Thus, the pulling handle 141can be readily expanded from the collapsed position P1 to the expandedposition P2 by the human operator 197 merely pulling the movable gripportion 164 obliquely upward. Thus, the operation for expanding thepulling handle 141 can be even further facilitated, which can evenfurther enhance the usability of the power generator apparatus 10.

Then, the pulling handle 141 is retained in the collapsed position P1where it is engaged by the handle holders 153 and 154, and thelongitudinal middle portion 138 c of the lower connecting rod 138engages the caster stopper 185. In this way, the steering wheel 126 ofthe caster section 61 can be prevented from undesirably pivoting aboutthe pivot shaft 124 and moving up and down.

Further, because not only the pulling handle 141 is engaged by thehandle holders 153 and 154 but also the right tire stopper 158 abutsagainst the outer periphery of the right tire 65, undesired rotation ofthe right wheel 56 can be prevented by the right tire stopper 158.Similarly, the left tire stopper (not shown) abuts against the outerperiphery of the left tire 65. Thus, undesired rotation of the leftwheel 58 can be prevented by the left tire stopper.

Also, the left and right leg portions 28 are lowered to the stationaryposition, so that the mobile power generator apparatus 10 can be stablyheld in a stationary position.

FIGS. 25A and 25B are views explanatory of an example manner in which apower cord is moved away from the left and right wheels by means of thepulling unit 16. Output terminal 202 is provided on an operation panel201 of the mobile power generator apparatus 10. Electric power generatedby the power generator apparatus 10 can be output by a plug of the powercord 203 being inserted in the output terminal 202. According to theembodiment, the mobile power generator apparatus 10 may be moved withthe plug 204 of the cord 202 kept inserted in the output terminal 202.

As the pulling handle 141 of the pulling unit 16 is expanded from thecollapsed position, the lower connecting rod 138 ascends to lift thepower cord 203. Thus, the power cord 203 can be moved away from the leftand right wheels by means of the pulling unit 16, so that it can beprevented from getting tangled with the left and right wheels.

Whereas the preferred embodiment has been described above in relation tothe case where the rim 64 of each of the wheels 56 and 58 is supportedat its three portions via the three guide rollers, i.e. first and secondfixed guide rollers 71 and 72 and movable guide roller 73, the presentinvention is not so limited; for example, the rim 64 may be supported atits four or more portions via four or more guide rollers.

Whereas the preferred embodiment has been described above in relation tothe case where the first and second fixed guide rollers 71 and 72 andmovable guide roller 73 are supported via the first and second fixedlymounting sections 75 and 76 and variably mounting section 77, thesemounting sections may be constructed in any other desired manner thanthe aforementioned.

Furthermore, whereas the preferred embodiment has been described asemploying the compression spring 117 as the resilient member of thevariably mounting section 77, the present invention is not so limited,and the resilient member may be a tension spring or the like.

The present invention is well-suited for application to mobile powergenerator apparatus where the power generator is mounted in a frame andwheels are attached to the frame for moving the power generator.

1. A mobile power generator apparatus comprising: left and right wheelsmounted to a frame having a power generator mounted therein at leastthree guide rollers provided, for each of the wheels, for rotatablysupporting a rim of the wheel at least three positions of the rim; andmounting means for respectively mounting the at least three guiderollers, provided for each of the wheels, on a side wall of the frame,each of the left and right wheels being rotatably supported by the atleast three guide rollers on one of the side walls of the frame.
 2. Themobile power generator apparatus of claim 1, which has a free space areaformed at and around a center of the rim of each of the wheels.
 3. Themobile power generator apparatus of claim 1, wherein one of the at leastthree guide rollers, provided for each of the rollers, is a movableroller supported via the mounting means in such a manner that themovable guide roller is movable in a radial direction of the rim, andthe movable guide roller is normally urged by a resilient member inresilient abutment against the rim.